Contact assembly



June 19, 1956 E. E. wlLLs 2,751,471

CONTACT ASSEMBLY Filed Feb. l2, 1953 4 Sheets-Sheet 1 June 19, 1956 E.E.wu 1 s CONTACT ASSEMBLY 4 Sheets-Sheet 2 Filed Feb. 12, 1953 f fi 7iINVENTOR. [APW/v W/z s TT/VEYS June 19, 1956 E. E. wlLLs 2,751,471

CONTACT ASSEMBLY Filed Feb. l2, 1953 4 Sheets-Sheet 5 June 19, 1956 E.E. w|| s 2,751,471

CONTACT ASSEMBLY Filed Feb. l2, 1955 4 Sheets-Sheet 4 @552% mi yu y :IMMl I INI/ENIOR.v ffy/N W/L 4 S 1 15.19; @MMM United States Patent OCONTACT ASSEMBLY Ervin E. Wills, Alton, Mo., assignor to FederalElectric Products Company, a corporation of Delaware ApplicationFebruary 12, 1953, Serial No. 336,515

11 Claims. (Cl. 20G-166) The present invention relates to electriccontact assemblies of the plug-in type.

Plug-in contact assemblies, of the type generally used, for example andnot by way of limitation, in a draw-out switch gear, comprise astationary blade like contact member and a companion movable plug-incontact member. The movable plug-in Contact member comprises aconducting carrier element provided, at one end thereof, with aplurality of pairs of contact fingers between which the blade contactengages. Heretofore, said ingers were tlxedly secured Vto the carrierelement and were usually suitably spring biased to provide the requiredcontact pressure, the fingers of each pair being urged apart uponengagement of the blade contact therebetween. However, the presence ofcorrosion or foreign matter at the point of securement or connection ofthe fingers to the companion carrier element tended to decrease currentliow through the movable plug-in contact member.

Therefore, the primary object of the present invention is to eliminatethe causes of the reduced current ow in plug-n contact members of theprior art.

Another object is the provision of a plug-in contact member wherein thecontact fingers are free of xed securement or connection to theircarrier element.

Another object is the provision in a plug-in contact member of means toprovide a wiping action between the Contact fingers and their carrierelement to provide clean contacting surfaces.

A further object is the provision of means, in a plugin contact memberprovided with a plurality of pairs of contact lingers, to stagger orreduce the force required to insert the stationary contact memberbetween the pairs of fingers or to Withdraw said stationary contactmember from the pairs of lingers.

The above and other objects, features and advantages of the presentinvention will be more fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. l is a perspective view of a plug-in contact assembly pursuant tothe present invention, the companion movable and stationary contactmembers being illustrated in the disengaged condition thereof;

Fig. 2 is an exploded view, on a larger scale, of a contact linger andspring of the movable contact member;

Fig. 3 is a plan View, on a larger scale of the disengaged contactassembly, with portions broken away and sectioned for purposes ofillustration;

Fig. 4 is a sectional view taken on the line 44 of Fig. 3, andillustrates the initial contact of the fingers of the movable contactmember with the stationary contact member;

Fig. 5 is a secional view taken on the line 5-5 of Fig. 4;

Fig. 6 is a sectional view taken on the line 6--6 of Fig. 4;

Fig. 7 is a view taken in the direction of the arrow 7 vin Fig. 3, andillustrates the wiping action which occurs rice during the movement ofthe movable contact member toward engagement with the stationary contactmember',

Fig. 8 is a view similar to Fig. 7 and illustrates an intermediateposition of engagement of the stationary contact member, between thecontact ngers;

Fig. 9 is a view similar to Figs. 7 and 8 and illustrates fullengagement of the stationary contact member between the contact ngers;

Fig. 10 is a view similar to Figs. 7, 8 and 9 and illus trates thewiping action which occurs during the movea ment of the movable contactmember to disengage the stationary contact member;

Fig. 11 is a plan view of the movable contact member pursuant to anotherembodiment of the invention, parts being broken away and sectioned forpurposes of illustration;

Fig. 12 is a sectional view taken on the line 12-12 of Fig. 11;

Fig. 13 is a view similar to Fig. 12, and illustrates an operativecondition of engagement of the companion contacts;

Fig. 14 is a view similar to Fig. 3 and shows a modication of themovable contact member;

Fig. 15 is a sectional view taken on the line 15-15 of Fig. 14 andillustrates the initial contact of the fingers of the movable contactmember with the stationary contact member;

Fig. 16 is a plan view of a movable contact member pursuant to anotherembodiment and modified as in Fig. 14;

Fig. 17 is a view taken in the direction of the arrow 17 in Fig. 16, andillustrates the initial engagement of a pair of contact lingers with thestationary contact member;

Fig. 18 is a view similar to Fig. 17 and illustrates the wiping actionwhich occurs during the movement of the movable contact member towardengagement withl the stationary contact member; and

Fig. 19 is a view similar to Fig. 16, showing the engaged condition ofthe contact assembly.

Referring now to Figs. l through 10 of the drawings in detail, there isillustrated a plug-in type contact assembly 20 constituted by thestationary blade-like contact member 22 and the companion movableplug-in device 24. It will be understood that the stationary contactmember 22 is suitably mounted in position and the movable contact member24 may be carried, as here shown, by a suitable portion 26 of a draw-outswitch gear or similar device, being secured thereto as by the securingelements 28. Y

The device 24 comprises a conducting part or carrier 30 which isprovided with a plurality of paired contact lingers or contact elements32. More specically, the contact member 24 is provided at the free end34 thereof with a substantially rectangular frame member or cage 36which is secured thereto as by the securing elements 49. It will benoted from Figs. 4 and 6 that the cage 36 is provided with a Wall 40thereof which extends trans'- versely and outwardly of the marginal edge42 ofthe conducting carrier 30, being preferably in abutment therewith.Said wall is provided with a plurality of longitudinally extending slots44, there being one slot 44 for each pair of opposing contact fingers32. The opposing wall portions 46 (Fig. 5) of the cage 36 are providedwith pairs of longitudinally aligned slots 48-48, each pair being inlateral alignment with a slot 44. Said wall portions are each providedwith a flange 47,.the securing elements 49V serving to secure said angesto the carrier 30. It will be noted that there is a slot 48 at each sideof the carrier 30. As here shown, and as presently constructed, thereare four long slots 44 in wall 40, each of which accommodates a pair ofopposing .s contact `lingers 32, and therelare eight short slots 48 inthe opposing wall 46, each of 'which accommodates a single Contactfinger, whereby to provide four contact fingers at each side -of thecarrier 30. However, it will be understood that it is within the scopeof theY present invention to increase or to decrease the number of pairsofcontact fingers.V Y

Pursuant to the present invention, the contact fingers 32 are mountedfor limited slidable movement relative to the carrier 30.

More specifically, as best shown in Fig. 2, each contact linger 32 isprovided at one side edge 54 thereof with a forward contact makingportion 50 and with a rearwardly disposed contact makingA portion 52.Said side edge 54 is also provided with an outwardly extending portion56 disposed intermediately of the spaced contact making portions 50and-52 thereof. Between the portion 56 andthe rear contact makingportion 52, the side edge 54 Vis provided with an open detent recess 58.The opposing marginal edge portion 60 is also provided with an openrecess 62 which constitutes a s'eat for a compam'on coiled spring 64, astub portion 66 being provided in said seat to prevent lateral movementof the spring in the seat, the spring biasing the contact finger againstthe carrier. i

Each contact finger 32 is mounted in the cage 36 so that it extendsthrough a long slot 44 andan opposing short slot 48. v Morespecifically, the forward contact portion 50 of the contact finger isdisposed outwardly of the frame wall 40 Aand the rear contact portion 52is disposed outwardly of the opposing frame wall 46. As will be readilyapparent from Figs. l, 4 and 7 through 10, the contact fingers 32 arepaired so that there is one contact linger atV each side of the carrier30in each of said pairs. In addition, it will be noted that the rearcontact portions 52 engage the adjacent surface of the carrier 30 andthat the forward contact portions 50 of each pair are in confrontingspaced disposition forwardly of the forward edge 42 of the carrier. Thecoiled spring 64 for each contact finger 32, has one end thereofdisposed over the stub 66 in the seat 62 thereof and the other end ofthe spring abuts'the adjacent end wall 68 of the frame 36. Each slot 4Sterminates adjacent the carrier member 30 in a wall portion 7G which isstraddled by the previously mentioned recess 58 and serves asa detenttherefor. Therefore, it will be understood, that the various fingers 32are mounted to eiect limited slidableV movement of the carrierV30relative thereto.Y Further, it will be .understood that said movement inone direction is limited by the engagement of the sideedge 76 of therecess 58 with the wall detent 70 as illustrated in Fig.Y 7, and saidmovement in the opposite direction is limited by the engagement of theopposite side edge 78 of the recess 5 8 Vwith said wall detent 70, asillustrated in Fig. l0.-

y It will be noted that the stationary contact 22 is rounded at the freeend thereof, as at 80 in order to facilitate the engagement of thestationary contact between the forward confronting contact portions 50of the lingers 32. Adjacent the rounded end 80 thereof, the stationarycontact is grooved at each side thereof,l as ,indicated Vat v82, for apurpose hereinafter described in detail.

, v Fig. 1 illustrates the disengaged condition of the contact Y.assembly 20. Assuming now that the movable contact member 24 is movedin a direction to engage the stationary contact 22, as indicated by thearrow 72 in Fig. 4, the rounded portion 80 of the stationary contactwill initially be engaged by the confronting forward contact portions 50of each pair of contact fingers 32, Vas best illustrated Vin'said gure.In thisy connection, it will be understood that the space betweenconfronting portions 50 of each pair of contactv fingers is less thanthe thicknessof the forward free end portion 80 of the stationarycontact. It will also be understood that the contact fingers 32 are eachdisposed within. the frame 26, inthe disengaged 'condition of thecontact assembly, so that each wall detent abuts the edge 78 of therecess 58. Continued movement of the carrier in the same direction,after said initial engagement, results in the wiping of the carriersurfaces on the rear contact portions 52 of the various Contact fingersuntil the opposite side edge 76 of each recess 58 is engaged by the walldetent, whereby to terminate said movement of the carrier relative toits contact fingers. Said latter position of the carrier is illustratedin Fig. 7. It will be apparent therefore, that during the continuousmovement of the carrier from the position thereof illustrated in Fig. 4to the position thereof illustrated in Fig. 7, due to the initialengagement' of the fingers with the stationary Contact 22, the opposingsurfaces of the carrier 30 will wipe on the contact portion 52 and onthe guide portion 56 of each finger and said wiping action will tend toremove, at the contact points between the carrier and its fingers, filmwhich may have formed on the surface of the carrier member, whetherthrough corrosion oxidation or otherwise, and will also wipe the carrier-member at said points, free of foreign material, to provide Vfor a goodelectrical contact between the ngers and the carrier member. Continuedmovement of the movable contact device in the same direction, nowresults in the entry of the stationary contact between the pairsV ofcontact fingers, as illustrated in Fig. S. In order to effect saidentry, the contact fingers yield or pivot outwardly and away from theadjacent surface of the carrier, the contact portions 52 thereof servingas fulcrums for said pivotal movement which occurs against the bias ofthe springs 64. Said springs are compressed upon entry of the stationarycontact between the companion fingers since the stationary contact isthicker than the space between each pair of forward contact portions 50of the fingers. The contact portions 50 ride over the edge 80 and intothe adjacent groove 82 and then out of the groove and onto the surfaceof the stationary contact member for effecting rm mechanical and goodelectrical contact therewith. Fig. 9 represents the fully inserted orengaged position of the stationary contact and the movable contactdevice, the springs pressing the contact portions 52 against the carrierand the contact portions 50 against the stationary contact member. Y

In order to disengage the companion contact members, the movable contactdevice is withdrawn fromY the stationary contact member in the directionof the arrow 84 in Fig. 10. Y

During said withdrawal, the contact lingers move with the carrier as aunit, the contact portions 50 riding on the surfaces of the stationarycontact member until they engage in the groove 82 thereof, being then inthe position thereof illustrated in Fig. 8, wherein the springsV biasthe contact portions 50 into the groove. Continued movement of thecarrier in the Vdirection of the arrow 84 in Fig. 10, now results in almovement of the carrier relative to its contact fingers until the walldetents 70 of the cage 36 abut the marginal edges or sides 78 of thevarious recesses 58 in the contact ngers, as illustrated in said figure.Therefore, it will be apparent that during the movement of the carrierinthe direction of the arrow 84, from the instantaneousl position thereofillustrated in Fig. y8, to the instantaneous position thereofillustrated in Fig. l0, there has occurred a wiping action of thecarrier surfaces against the contact portions 52 of the various contactfingers. Consequently, it will be noted that two separate wiping actionsoccur, the first wiping action occurring upon the engagement of themovable contact device with a stationary contact member, and the secondwiping action occurring upon the disengagement of the movable contactdevice from the stationary contact member. It will also be noted thatsaid second wiping action conditions thevcontact lingers forva-repetition of the iirst wiping action upon the next engagement of themovable contact device with the stationary contact, as will `be apparentfromFigs. l0 and 4. :.Continued m0YmQ11 'construction of the movablecontact device.

in the direction of the arrow 84, now results in the pivotal or yieldingmovement of the various contact elements, against the bias of thesprings thereof, as the rounded portion of the stationary contact passesbetween the confronting contact portions 50 of each pair, the variousContact fingers pivoting about the contact portion 52 thereof until thecontact fingers disengage the stationary contact, whereupon the springsthereof expand and the fingers resume their normal disengaged conditionas illustrated in Fig. l.

Figures 14 and l5 illustrate a modification in the Pursuant to saidmodification, the springs 64 are replaced by leaf springs 86. In orderto accommodate said leaf springs, the opposing end walls 68A of theframe or cage 36A are provided with the slotted portions 8S. It will benoted from Fig. 14, that two aligned slotted portions 88 are providedfor each leaf spring 86. In order to mount the leaf spring in the cage36A, the spring is provided with the confronting struck-up portions90-90. Each struck-up portion is disposed within a slotted portion 88 ofthe cage 36A and abuts the inner marginal edge 92 of its companionslotted portion. lt will be noted that the contact fingers 32A are notprovided with the recessed portion or seat 62, as in the contact ngers32. The opposite ends of the springs 86 extend outwardly from the cage36A to bias the opposite ends of the contact fingers 32A toward thecarrier thereof. In all other respects, the movable contact device 24Afunctions in the same manner as the movable contact device 24 to providefor a wiping action both upon the engagement and the disengagement ofthe contact assembly as previously described, Fig. 15 illustrating inbroken line, movement of the carrier 30 relative to the contact fingersfor the wiping action upon movement of the carrier in the direction ofarrow 72.

Referring now to Figs. 1l, l2 and 13 there is illustrated anotherembodiment of the present invention. Pursuant to the present embodiment,the force which is required to effect the engagement and thedisengagement of the contact assembly is reduced. In the previouslydescribed embodiment, it was necessary to pivot or yield all of thecontact elements at the same time against the bias of their respectivesprings in order to engage or disengage the stationary contact memberbetween the various pairs of contact ngers. However, pursuant to thepresent embodiment the pairs of fingers yield in sequence upon theengagement or disengagement thereof with the stationary contact member.The movable contact device 24B of the present embodiment, differs fromthe movable contact device 24 of Fig. l, in that the contact lingers 32of the latter are all of the same longitudinal dimension, whereas thecontact fingers of the present embodiment are of different longitudinaldimensions, respectively. The shortest pair of contact fingers 94 areeach substantially of the same longitudinal dimension as the contactfingers 32. The pair of contact fingers 96 are each longer than thecontact fingers 94. The pair of contact fingers 98 are each longer thanthe contact fingers 96, and the pair of contact fingers 100 are eachlonger than the contact ngers 98. However, it will be noted that in allother respects the contact fingers of the movable contact device 24B aresubstantially similar to the previously described contact fingers 32,each being provided with a coiled spring 64 and with a recess 58 aspreviously described. The contact fingers of the present embodiment aremounted Within the cage or frame 36 in the same manner as described inconnection with the plug-in device 24. Itt will be noted from Figs. 1land l2, that in the disengaged condition of the contact assembly, therear contact making portions 52 of the various contact fingers of themovable contact device 24B are in alignment, the forward contact makingportions S0 thereof being in staggered relationship. It will also beunderstood, that in each of said contact fingers,thereessed portioniSS 6thereof is at the same distance from the companion contact makingportion 52.

Assuming now that the contact assembly is being closed, so that thecarrier 30 of the movable contact device 24B is being moved in thedirection of the arrow 102 in Fig. i3 toward the stationary contactmember 22, it will be apparent that the stationary contact will first beengaged by the pair of longest contact fingers 100. Upon said initialengagement and due to the continuous movement of the carrier 30 in thedirection of the arrow 102, the carrier surfaces will wipe past thecontact portions 52 of the Contact fingers 100, in the same manner aspreviously described. At the termination of said wiping action, thengers 100 will yield against the bias of their springs 64 to engage thestationary contact member 22 therebetween, in the same manner aspreviously described. However, as said lingers 100 begin to yield, thenext pair of lingers 98 will have been carried into initial engagementwith the stationary contact. Consequently, as the fingers 100 are ridingover the forward portion of the stationary Contact, the carrier 30 iswiping against the rear contact portions 52 of the fingers 98. At theterrnination of the wiping action of the fingers 98, the various fingerswill be disposed substantially in the position thereof illustrated inFig. l3. It will be noted that in said position, the longest fingers 100have already ridden out of the grooves 82 of the stationary contactmember, and are disposed on the surfaces thereof rearwardly of saidgrooves. Consequently, it will be apparent that up until this point, theonly energy that was required was the energy necessary to yield thecontact fingers 100 away from each other against the bias thereof, toride said fingers over the end of the stationary contact 22 into thegrooves thereof and to ride said contact fingers out of the grooves andonto the surfaces of the stationary contact member. Continued movementof the carrier 30 in the direction of the arrow 102, causes the contactfingers 98 to yield in order to ride over the rounded end of thestationary Contact member 22 to the position of the contact fingers 100in Fig. 13. During said movement of the contact fingers 98 onto thestationary contact member, the latter has engaged the next pair ofcontact fingers 96 to eiect the wiping action of the carrier 30 relativeto said contact fingers 96. As the contact fingers 96 yield to ride overthe rounded end of the stationary contact member, the latter engages thelast pair of contact fingers 94 and the wiping action occurs between thecarrier 30 and the contact portions 52 of the contact fingers 94. At thetermination of the movement of the contact device 24B for the fullyengaged conditionV thereof with the stationary contact member, theshortest Contact fingers 94 have ridden out of the grooves in thecontact member 22 onto the surfaces thereof rearwardly of said groove.Therefore, it will be apparent that in effecting the full engagement ofthe movable contact device 24B with the stationary contact member 22,the latter is sequentially engaged by the various pairs of fingers sothat the maximum force or energy required at any one time is thatnecessary to effect the yielding movement of only one pair of contactfingers to move the latter over the rounded portion 80 of the stationarycontact 22 and onto the surfaces thereof.

In order to effect the disengagement of the movable contact device 24Bfrom the stationary contact member, the carrier 30 is withdrawn in adirection opposite to the arrow 102. All of the contact ngers initiallymove as a unit with the carrier 30, until the shortest contact fingers94 engage in the grooves of the stationary contact. This results in awiping action of the carrier 30 against the contact portions 52 of theshortest fingers 94 and upon the termination of said wiping action, dueto said continuous movement of the carrier, the fingers 94 yield awayfrom each other to ride out of the grooves and over the rounded edge 80to disengage the stationary contact member. As the fingers 94 areyielding to ride over-.the rounded edge portion 80 of thestationaryconcarrier and the latter.

tact, thenext pairV of fingers 96 reach thegrooves 82 and the wipingaction occurs between said lingers 96 'andV the carrier V30.- By thistime, the lingers 94 are completely disengaged from the stationarycontact 22, and as the Ytingers-961yield in order to ride over the edgeof the stationary contactthe succeeding pair of lingers 98 engage inthegrooves 82 to eect the wiping action between the The same action isrepeated with respecttothe longest ngers 1 00 as the lingers 98 rideover the edge of the stationary contact to disengage the latter, Vtheaction being terminated when the longest lingers .100 disengage thestationary contact. From the foregoing, it will be apparent that atanyone time during the.V movement of the movable contact device 24B todisengage the 'stationary contact 22, only one pair of its contactlingers are yielding. Therefore, it will be readily apparent that bothYupon the engagement and disengagement of the movable contact device24B, it is necessary at any one time to supply energy or forcesufficient only to yield one pairA of contact lingers, whereby tomaterially reduce the energy required at any one time to eliect theyielding of the fingers, when compared with the energy required in theembodiment of Fig. 1 wherein all of the lingers yield at the same time,both upon the engagement and the disengagement of the movable contactdevice.

, Referring now to Figs. 16, 17, 18 and 19, there is shown amodilication of thepreviously described embodiment of Pigs. 11, 12 and13, pursuant to which the modification of Figs. 14 and 15 isincorporated in this embodiment. Pursuant to the present embodiment,theV cage or frame 36A ofFigs. 14 and 15 having the slotted portions 88in the end walls 68A thereof, is utilized for mounting the leaf springs86 which are similar to the similarly numbered springs in Figs. 14 and15, and for mounting the shorter leaf springs 86A. It Will be understoodthat the longer springs 86 and the shorter springs 86A are each providedwith the struck-up portions 90, as illustrated in Fig. 15, for mountingthe springs in the end walls 68A of the cage 36A. Pursuant to thepresent embodiment, an energy or force staggering elect, similar to thatdescribed in connection with Figs. 11, 12 and 13 is achieved. In thepresent embodiment the various contact lingers are all of the samelongitudinal dimension, as best illustrated in Fig. A16, however, saidfingers differ in the dimension of the recessed detent portions delinedtherein. It will be noted that as presently constructed, there are twopairs of the lingers 104 and two pairs of the fingers 106. The lingers104 are provided with recesses 5S which are similar in dimension to therecesses 58 in the embodiment of Figs. 1-10. However, the lingers 106are provided with recesses 58A which are substantially longer than therecesses 58. It will be understood that the distance between the side 78of the short recess 58 and the contact making portion 52 ofthe companionlinger, is the same as the distance between the similar side 78 of thelonger recess 58A and the contact making portion 52 of the ngerassociated with the latter. Therefore, it will be apparent that in thedisengaged condition of the movable contact device 24C, the sides 78 ofall of the recesses on the same side of the carrier 30 are in alignment,transversely of the carrier. However, it will be noted that the opposingsides of the recesses are not in alignment. More specifically, the sides76A of the longer recesses aredisposed forwardly of the similar sides 76of the shorter recesses. Inaddition, it will be-noted that the longersprings 86 are associated with the lingers 104 having the shorterrecesses S8, and the shorter springs 36A are associated with the lingers106 having the longer recesses 58A.

In order to engage the movable contact device 24C with the stationarycontact member, 22, said device is moved in the direction of the arrow108 in Fig. 17. This results in the initial simultaneous engagement ofall of the contact lingers with the stationary contact member 22, as

.illustrated in Fig. 17 Continued movement of the carrier in the samedirection, results in a wiping. action of all 'of the contact lingersrelative to the carrier. a insofar as the lingers `104 are concerned,this wiping action terminates prior to the wiping action of the lingers106. Thisre'sults frornthe fact that the lingers 104 have the shorterrecesses 58. Consequently, when the sides 76 ofthe shorter recesses 58engage the wall detents 70, as illustrated in Fig.` 18, wherein thecarrier 30 has moved Yfrom the position thereof illustrated in Fig. 17toward theV stationary contact member, the lingers 104 begin to yieldagainst the bias of the springs 86 thereof to ride over the forward edgeof the stationary contact member. However, as illustrated in Fig. 18,the `corresponding sidesg7 6A of the longer slots 58A in the fingers 106have not as yetrbeen engaged by the companion wall detents 70.Therefore, the wiping action of the carrier 30 relative to the contactportions 52 of the lingers 106 continues as the lingers 104 ride overthe edge 80 and out of the groove 82 of the stationary contact onto thesurfaces thereof. At about the time that the forward contact portions 50of the lingers 104 ride out of the grooves of the stationary contactmember, the ldetent portions 70 engage the ends 76A of the longerrecesses 58A in the lingers 106. The wiping action of the carrier 30relative to the lingers 106 now terminates and said lingers begin toyield against their companion springs to ride over the edge 80 and outof the groove 82 onto the surfaces of the stationary contact 22.Therefore,'it will be apparent that it was not necessary to eliect thesimultaneous yielding of all of the contact lingers during theengagement of the movable contact device 24C with the f stationarycontact 22. The force required was that necessary to rst yield the pairsof contact lingers104, and after the latter were riding on the surfacesof the stationary contact member, force or energy was again required toyield the pairs of contact lingers 106 for effecting the engagementthereof on the surfaces of the stationary contact rearwardly of thegrooves therein. lt will be apparent, that upon disengagement of themovable contact device 24C, the required energy is again divided. Due tothe differences in the lengths of the recess SS and 58A, respectively,when the movable contact device 24C is fully engaged with the stationaryContact 22, the contact making portions 50 of the fingers 104 will bedisposed at a greater distance rearwardly of the edge 80 of thestationary contact member than will be the contact making portions 50 ofthe lingers 106, as illustrated in Fig. 19. Consequently, upon movementof the movable contact device inthe opposite direction to disengage thelingers thereof from the stationary contact, the portions 50 of thelingers 106 will engage in the grooves 82 before the engagement of thesimilar portions 50 of the lingers 104 in said grooves 82. This resultsin a wiping action between the carrier 30 and the contact makingportions 52 of the lingers 106 prior to wiping action between thesimilar portions 52 of the fingers 104 and the carrier 30. However, dueto the relationship of the dimension of theslot 58 relative to the slot58A, the wiping action of all of said lingers relative to the carrier 30will terminate at substantially the same time, namely when the ends 78of both the slots 5S and the slots 58A will be in lateral alignment ateach side of the carrier 30. Thereupon, continued movement of thecarrier in the same direction will effect the simultaneous disengagementof all of the fingers from the stationary contact member. In thisconnection, it will be'noted that the various fingers are now disposedrelative to the carrier 30, as in Figure 17, whereby they are incondition for a following wiping action upon movement of the movablecontact device 24C in a direction to engage the stationary contactmember.

1. In a contact assembly having companion relatively movable contacts,one of said contacts comprising a conducting part and a part foreffecting electrical connection of said conducting part and the other ofsaid contacts, said parts having electrically contacting portions, andsaid parts being relatively movable in wiping relation when saidcontacts are brought into engagement, and said other contact havingmeans cooperating with said electrical connecting part to condition thelatter for said wiping movement.

2. In a contact assembly having companion relatively movable contacts,one of said contacts comprising a conducting part and a part foreiecting electrical connection of said conducting part and the other ofsaid contacts, said parts saving electrically contacting portions, andsaid parts being relatively movable in wiping relation when saidcontacts are brought into engagement, said other contact having aportion slidably engageaole by said electrical connecting part, and saidlast mentioned portion having means to interrupt slidable movement ofsaid e1ectrical connecting part thereon whereby to condition the latterfor said wiping movement.

3. In an electric contact assembly, a contact device comprising aconducting carrier having a pair of opposing contact elements adapted toreleasably engage a companion contact therebetween, and means providingfor relative movement of said carrier and contact elements in wipingrelation when said contacts are brought into engagement, and saidcompanion contact having means cooperating with-said elements tocondition the latter for said wiping movement.

4. ln an electric contact assembly, Va contact device comprising aconducting carrier having a pair of opposing contact elements adapted toreleasably engage a companion contact therebetween, and means providingfor relative movement of said carrier and contact elements in wipingrelation, whereby to provide for wiping action between said carrier andsaid elements, said means being frame means provided on said carrier forsaid contact elements, said frame means and said contact elements havingcooperating portions for limiting said relative movement, resilientmeans operatively interposed between said frame and said contactelements to bias the latter toward each other, and means for causingsaid relative wiping movement iirst in one direction and then in theother during engagement and disengagement, respectively, of said otherof said portions with said companion contact.

5. In an electric contact assembly, a contact device comprising aconducting carrier having a pair of opposing contact elements adapted toreleasably engage a companion contact therebetween, and means providingfor relative movement of said carrier and contact elements in wipingrelation, whereby to provide for wiping action between said carrier andsaid elements, and said companion Contact being a blade memberengageable between said contact elements, said blade member havinggrooved means engageable by said contact elements upon opening andclosing, respectively, of said contact assembly, whereby to conditionsaid Contact elements for wiping actions upon said opening and closing,respectively, of said Contact assembly.

6. In an electric contact assembly, a contact device comprising aconducting carrier having a pair of opposing contact elements adapted toreleasably engage a companion contact therebetween, and means providingfor relative movement of said carrier and contact elements, whereby toprovide for wiping action between said carrier and said elements, saidmeans being frame means provided on said carrier for said contactelements, said frame means and said contact elements having cooperatingportions for limiting said relative movement, said contact elementshaving portions projecting from opposite sides, respectively of saidframe means, one of said portions being in sliding contact with saidcarrier and the other of said portions being engageable with saidcompanion contact and means for causing said relative movement first inone direction and then in the other during engagement and disengagementrespectively of said other of said portions with said companion contact.Y

7. In a Contact assembly having companion relatively movable contacts,one of said contacts comprising a conducting carrier having a pair ofopposing contact elements and the other of said contacts beingreleasably engageable therebetween, said contact elements extending inthe direction of said relative movement and being mounted on said onecontact, for movement of the latter relative thereto in wiping relationtherewith, whereby to provide for wiping action between said carrier andsaid contact elements, respectively, and said other contact havingportions engageable by said contact elements upon opening and closing,respectively, of said contact assembly, whereby to condition saidcontact elements for wiping action upon said opening and closing,respectively, ot said contact assembly.

8. In an electric contact assembly, a contact device comprising aconducting carrier having a contact element adapted to make engagementwith a companion contact, said contact element being mounted forrelative movement in wiping relation with its conducting carrier from afirst position to a second position to thereby make wiping contacttherewith, means causing said contact element to move from said firstposition to said second position when said element is making engagementwith said companion Contact and for causing said contact element to moveback to said tirst position when being disengaged therefrom.

9. In an electric contact assembly, a contact device comprising aconducting carrier having a pair of opposing F contact elements adaptedto releasably engage a companion contact therebetween, said contactelements being mounted for relative rectilinear movement with respect totheir conducting carrier from a rst position to a second position tothereby make wiping contact therewith, means causing said contactelements to move from their said first positions to their said secondpositions when said elements are making engagement with said companioncontact and for causing said contacts to move back to their said rstpositions when being disengaged therefrom.

10. In an electric contact assembly, a contact device comprising aconducting carrier having a pair of opposing contact elements adapted toreleasably engage a companion contact therebetween, said contactelements being mounted for relative rectilinear movement with respect totheir conducting carrier from a rst position to a second position tothereby make wiping contact therewith, means causing said contactelements to move from their said first positions to their said secondpositions when said elements are making engagement with said companioncontact and cooperating means on said companion con tact for causingsaid contacts to move back to their said first positions when beingdisengaged therefrom.

11. In a contact assembly having companion relatively movable contacts,one of said contacts comprising a conducting part and a part foreffecting electrical connection of said conducting part and the other ofsaid contacts, said parts having electrically contacting portions, andsaid parts being relatively slidably movable for providing wiping actionat said portions thereof, and said other contact having meanscooperating with said electrical connecting part to condition the latterfor said wiping action.

References Cited in the le of this patent UNITED STATES PATENTS1,740,640 Austin Dec. 24, 1929 1,978,246 Bauerschmidt Oct. 23, 19342,454,788 Frese Nov. 30, 1948

